package com.example.mybatisdemo.config;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceAutoConfigure;
import com.alibaba.druid.spring.boot.autoconfigure.properties.DruidStatProperties;
import com.alibaba.druid.util.Utils;
import org.springframework.boot.autoconfigure.AutoConfigureAfter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.servlet.*;
import java.io.IOException;

/**
 * @ClassName FilterRegistrationBean
 * @Author 刘泽
 * @Mail liuze713@hotmail.com
 * @Date 2021/12/22 6:08 PM
 * @Version 1.0
 */
@Configuration
@ConditionalOnWebApplication
@AutoConfigureAfter(DruidDataSourceAutoConfigure.class)
@ConditionalOnProperty(name = "spring.datasource.druid.stat-view-servlet.enabled", havingValue = "true", matchIfMissing = true)
public class RemoveDruidAdConfig {


  /**
   * 方法名: removeDruidAdFilterRegistrationBean
   * 方法描述:  除去页面底部的广告
   *
   * @param properties
   * @return org.springframework.boot.web.servlet.FilterRegistrationBean
   * @throws
   */
  @Bean
  public FilterRegistrationBean removeDruidAdFilterRegistrationBean(DruidStatProperties properties) {
    // 获取web监控页面的参数
    DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();
    // 提取common.js的配置路径
    String pattern = config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*";
    String commonJsPattern = pattern.replaceAll("\\*", "js/common.js");

    final String filePath = "support/http/resources/js/common.js";

    //创建filter进行过滤
    Filter filter = new Filter() {
      @Override
      public void init(FilterConfig filterConfig) throws ServletException {
      }

      @Override
      public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        chain.doFilter(request, response);
        // 重置缓冲区，响应头不会被重置
        response.resetBuffer();
        // 获取common.js
        String text = Utils.readFromResource(filePath);
        // 正则替换banner, 除去底部的广告信息
        text = text.replaceAll("<a.*?banner\"></a><br/>", "");
        text = text.replaceAll("powered.*?shrek.wang</a>", "");
        response.getWriter().write(text);
      }

      @Override
      public void destroy() {
      }
    };
    FilterRegistrationBean registrationBean = new FilterRegistrationBean();
    registrationBean.setFilter(filter);
    registrationBean.addUrlPatterns(commonJsPattern);
    return registrationBean;
  }
}
